Kano , Nigeria -LRB- CNN -RRB- Hundreds of troops from Chad and Niger launched a ground and aerial offensive against Boko Haram in northeastern Nigeria on Sunday , according to residents and military sources from Niger .

The sweeping offensive is taking place along the Niger-Nigeria border , sources said , effectively opening a new front in the fight against the Islamist terror group .

This comes a day after Boko Haram pledged allegiance to ISIS in an audio message purported to be from leader Abubakar Shekau .

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`` Early this morning , troops from Niger and Chad launched ground and air raids against Boko Haram into Nigeria , and the operation is still continuing , '' said a military official in the border town of Diffa , Niger .

`` It is an intensive operation that is aimed at pulverizing Boko Haram and crippling their capability , '' according to the source . He spoke on condition of anonymity because he is not authorized to comment publicly about the operation .

Residents said artillery fire and fighter jets pushed Boko Haram fighters into the Damasak district of Nigeria , which is a Boko Haram enclave .

`` Around 6 a.m. , soldiers from Niger and Chad in huge numbers confronted Boko Haram around the Doutchi area outside Diffa and later crossed the bridge into Nigeria , '' said Diffa resident Ari Boubakarna .

`` We heard huge explosions from artillery fire and fighter jets , but the explosions receded as the troops moved further into Nigeria , '' Boubakarna continued .

A journalist working in Diffa saw troops headed toward the border with Nigeria , where Boko Haram fighters had taken up positions .

`` They left in a huge convoy of over 200 vehicles , some of them fitted with machine guns , including armored tanks , ambulances , water tankers and cargo trucks , which indicate they were going for a prolonged operation , '' the journalist said .

Residents lined up the streets to offer water and tea as the troops drove out of Diffa , residents said , adding that soldiers promised to capture Shekau alive .

Another contingent of troops , backed by air support , moved out from the town of Bosso , Niger , according to residents .

`` Soldiers in large numbers crossed into Nigeria this morning , and we could hear thunderous sounds of gunfire and explosions coming from the direction of Malam Fatori , '' Bosso resident Tandja Moumouni said .

Nigeria and its neighbors have recently mounted a coordinated offensive against Boko Haram militants in the Borno state , where the Islamist group has seized a large swathe of territory . Nigeria shares a border with Niger , Chad and Cameroon there .

As a part of this alliance , thousands of troops from Niger and Chad were stationed in Bosso and Diffa in January .

The offensive has succeeded in reclaiming some of the territory seized by the group .

Nigeria has vowed to liberate all of its territories from Boko Haram before the general elections , which begin on March 28 , to enable displaced residents return to their homes for the elections .

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Troops from Chad and Niger launch offensive against Boko Haram

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The offensive is part of a coordinated regional campaign